Chinese Mini Lathe

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Chinese Mini Lathe

This topic has 24 replies, 17 voices, and was last updated 7 October 2013 at 00:18 by Bob Clare.

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19 September 2013 at 09:50 #17169
Packmule
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@packmule
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19 September 2013 at 09:50 #130108
Packmule
Participant
@packmule
Just a shot in the dark ,but.

has anyone any experience with the Mossfits on the PCB. The ones that are used are listed as discontinued and no data sheets are available to cross reference .

Thanks for any info,

Bob
19 September 2013 at 10:18 #130115
John Shepherd
Participant
@johnshepherd38883
Bob

If you say which make and model of lathe and the markings on the MOSFETs I might have a chance at helping you.
19 September 2013 at 11:19 #130121
Les Jones 1
Participant
@lesjones1
Hi Bob,
If you give some more information there is more chance that you will get help. What is the part number of the mosfets (Are you sure that they are mosfets ?) What is the part number of the board or post a picture of the board.

Les.
20 September 2013 at 14:31 #130264
John Rudd
Participant
@johnrudd16576
Bob,

The typical Sieg pcb that is mosfet based uses IRFP450 mosfets.

Ebay is a typical source for new ones…

Edited By John Rudd on 20/09/2013 14:42:10
22 September 2013 at 18:06 #130453
Packmule
Participant
@packmule
Hi guys,

sorry for the delay in posting a reply. I couldn't find my camera.

I have posted some photos of the offending board so you can see the parts and numbers.

The board has been tested and the other componants seem to be fine just thes mossfets. I can't find any data sheets so as to cross ref .So in the dark really unless you have any ideas. Its the two mossfets on the left that are causing the problem A69108 .But a alternative for all would be great.

Thanks for your time

Bob
22 September 2013 at 19:20 #130463
Anonymous
Errr, what makes you think that they're MOSFETs? The ref idents seem to be SCR1 and SCR2, which rather implies that they're SCRs.

Regards,

Andrew
22 September 2013 at 19:41 #130466
Oddlegs
Participant
@oddlegs
Hi,

They are SCRs, S8020L might be a suitable alternative (Farnell etc)

Regards,

John
22 September 2013 at 19:45 #130467
Sub Mandrel
Participant
@submandrel
As does a google search on "A69108 equivalent".

That looks like a US controller board, the chinese boards shipped in the UK output nearer to a scary 350V DC and look completely different.

The fault may be elsewhere if you are testing SCRs expecting them to be mosfets.

Neil
22 September 2013 at 20:33 #130473
Les Jones 1
Participant
@lesjones1
Hi Bob,
This information on these speed controllers suggest that the power devices are SCR's (As others suspect.) not MOSFETS as you suspect. The info in the link suggests that these devices are S8010L or S8020L both of which are available from Farnell.

Les.
22 September 2013 at 20:34 #130474
Pat Bravery
Participant
@patbravery
If you google the model number thats on the motor KBLC-240D you will find a lot of information about it, I suspect that the board is from a mini lathe, if so which one? Best regards Pat
22 September 2013 at 20:49 #130476
Pat Bravery
Participant
@patbravery
Just found on Amadeal's site new boards at £85.00 if all else fails, regards Pat
22 September 2013 at 22:46 #130487
John Haine
Participant
@johnhaine32865
KB controls are scr based, not MOSFET. On mine when it recently stalled, the fuse blew. Are you sure it isn't just a fuse?
23 September 2013 at 09:41 #130506
John Rudd
Participant
@johnrudd16576
Just to add, the scr's used are 'isolated tab' take this inot account if you need to change them……….

Which in my experience is unusual for them to blow (as long as the fuses are not changed for incorrect values) and I've repaired many of these boards…
30 September 2013 at 19:47 #131091
Packmule
Participant
@packmule
Whoops…

Sorry guys …….senior moment me thinks (some daft buggers about aint there)

You were correct they are SCRs ,but still causing problems .All this only happened because the speed sensor was diconected and reconnected ( power off &nbsp As soon as it was powered up it blew the fuse and this is where I've ended up. Will check to see the replacements are isolated and see how we go.

Thanks to everyone for their replies , will try and get it right next time

Thanks again,

Bob
30 September 2013 at 20:48 #131106
Grizzly bear
Participant
@grizzlybear
Hi Packmule,

Suggest you make a simple SCR tester, if you don't possess one.

Otherwise its all guesswork.

Regards, Bear..
1 October 2013 at 00:42 #131121
Bob Clare
Participant
@bobclare74748
I've just taken delivery of a brand new Warco Super Mini Lathe. This reply is therefore not really related to the above but is by way of a warning. Maybe the Forum Master should move this to another topic or use it to start a new one.

The unit was unpacked this morning and would have been set up except that the "instruction" booklet, if you could call it that, was for the old Warco Mini so the switch layout etc. was nothing like the Super Mini. In any case, the content was so meagre that it would have been difficlut to have used the booklet even on the old design.

I rang Warco asking for an decent instruction book for the Super Mini. The response was "there isn't one". So, I now have a nice new lathe (nice for the price anyway) and a load of ancillaries (gear wheels etc) with no way of knowing what goes where to achieve which, except by trial and error.

In addition, the arbor supplied for the tail stock chuck had a tang which meant that over an inch of the scale on the travel was lost, or the arbor was ejected! Did they have an arbor for the job? No they didn't – I ground off the tang.

I am less than impressed with Warco UK as you may imagine. So please beware of buying their products unless you're sure you know more than the UK supplier appears to.

Finally, has anyone any idea where I can get sensible instructions for this lathe? If not then I'll try writing some as I gain information and post the result. I'm used to a 1927 4¹/₂^“Southbend lathe for which I have a complete and comprehensive set of manuals.

ARC
1 October 2013 at 00:49 #131122
jason udall
Participant
@jasonudall57142
ARC…sorry can't help you myself.

but I suggest starting new thread..perhaps referencing you lathe make/model in the title..

just so it doesn't get overlooked.
1 October 2013 at 09:52 #131132
dcosta
Participant
@dcosta
Hello ARC. Good morning.

I do not know if it is useful for you, but I suggest you to take a look at the manual from LittleMachineShop you can found by visiting the following **LINK** .
It's apparently intended for the same machine with another badge and another color.

Best regards
Dias Costa
1 October 2013 at 11:52 #131146
Martin W
Participant
@martinw
Hi ARC

A manual for a similar model can be found here at Grizzly. I think you will find that quite a few of the UK suppliers, not just Warco, of these small machines tend to offer only very cut down manuals with their machines. It seems to have been a gripe for many years but it would seem to be one of the ways they use to keep costs down but all same it is very frustrating.

Welcome to the forum and I hope you enjoy using your new acquisition.

Martin W
3 October 2013 at 00:12 #131397
Bob Clare
Participant
@bobclare74748
Thanks to those who responded so quickly to my plea for a manual for the Warco Super Mini Lathe. Both the above suggested sources gave very useful info.

This thread, or should I say "sub-thread" has also woken Warco up and they are sending another manual. I will report on whether this is better than their last attempt.

Only one further problem has been spotted and that relates to the collar scale on the tail-stock drive. I ordered an imperial version of the lathe and largely received one with the exception of this collar where the scale is metric.

My former QA managerial resposibilities lead me to believe that Warco are hardly up to aerospace standars in that department!

Thanks again to the responders.

ARC (Bob Clare)
3 October 2013 at 02:17 #131401
Barry McDowell
Participant
@barrymcdowell95834
It's a shame customer service has slipped so far these days.

Barry
3 October 2013 at 07:49 #131405
Russell Eberhardt
Participant
@russelleberhardt48058
Posted by Bob Clare on 03/10/2013 00:12:21:

My former QA managerial resposibilities lead me to believe that Warco are hardly up to aerospace standars in that department!

Fortunately for us otherwise we would be paying aerospace prices!

Russell
3 October 2013 at 09:07 #131413
John Stevenson 1
Participant
@johnstevenson1
Good job you never bought a Myford ML2, Winfield, Pooles, Randa or similar lathe then as none of these ever had a manual.

Whilst i can understand the problems for a total newbie with some of these Chinglish manuals you have a well documented 4 1/2" South Bend.

Can't you use it ?

Reason I ask is lathes are like cars, they have a wheel at each corner and all drive the same.
7 October 2013 at 00:18 #131891
Bob Clare
Participant
@bobclare74748
I said I'd report on the quality of any fresh manual Warco sent, so here goes. I received not one but two copies of a much more comprehensive booklet which gave details regarding thread cutting etc. which were not in the one sent with the machine.

However, this version still only related to the "variable speed mini-lathe" i.e. the old model. Such items as the tail-stock "over centre lock" are not covered. That is a shame because after only a couple of days the top thread on the through spigot connected to the sub-bed clamp plate, stripped. This spigot is clearly just a standard M10 coach bolt quality stud. I had fun dismantling the thing, reversing the spigot and reassembling. I intend to make up a much better job.

I am glad to report that I successfully used this new lathe to complete on of "Artisan's" captive spindle steam valves suitably modified for use in the Martin Evans "Princess of Wales" backhead turret. Cutting and threading the stainless spindle was a real pleasure compared with doing the same tiddly job on the Southbend!

More may follow.

ARC
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